EFFECT OF EXPLOSIVE-TYPE STRENGTH TRAINING AND SHORT-TERM DETRAINING ON RATE OF TORQUE DEVELOPMENT DURING ISOMETRIC KNEE EXTENSION

2013 ◽  
Vol 47 (17) ◽  
pp. e4.45-e4
Author(s):  
Y Kobayashi ◽  
K Hirayama ◽  
T Matsubayashi ◽  
R Akagi
Keyword(s):  
Strength Training ◽  
Knee Extension ◽  
Short Term ◽  
Rate Of Torque Development ◽  
Isometric Knee Extension ◽  
Torque Development

The Acute Effects of Fast-Paced Walking on Isometric Peak Torque and Rate of Torque Development in Regularly Exercising and Inactive Older Women

2021 ◽  
pp. 1-7
Author(s):  
Ty B. Palmer ◽  
Jarrod Blinch ◽  
Ahalee C. Farrow ◽  
Chinonye C. Agu-Udemba ◽  
Ethan A. Mitchell
Keyword(s):  
Physical Activity ◽  
Older Women ◽  
Peak Torque ◽  
Knee Extension ◽  
Acute Effects ◽  
Rate Of Torque Development ◽  
Isometric Knee Extension ◽  
Before And After ◽  
Inactive Group ◽  
Torque Development

This study aimed to examine the acute effects of fast-paced walking on isometric peak torque and rate of torque development (RTD) in regular exercising and inactive older women. Ten regular exercising (67 ± 4 years) and 10 inactive (68 ± 4 years) older women performed three isometric knee extension contractions before and after a control condition (quiet resting) and an experimental condition of fast-paced walking for 6 min. Peak torque and early (RTD100), late (RTD200), and maximum (peak RTD) RTD measurements were obtained from each contraction. Results showed no significant changes in peak torque, peak RTD, or RTD200 after walking for either group (p > .050). A significant decrease in RTD100 was observed after walking for the inactive group (p = .005) but not for the regular exercisers (p = .909). These findings highlight the importance of physical activity and suggest that a task as simple as walking may impair the rapid strength capacities of inactive older women.

scholarly journals Fast Unilateral Isometric Knee Extension Torque Development and Bilateral Jump Height

2006 ◽  
Vol 38 (10) ◽  
pp. 1843-1852 ◽  
Author(s):  
CORNELIS J. DE RUITER ◽  
DANIEL VAN LEEUWEN ◽  
ARJAN HEIJBLOM ◽  
MAARTEN F. BOBBERT ◽  
ARNOLD DE HAAN
Keyword(s):  
Knee Extension ◽  
Jump Height ◽  
Isometric Knee Extension ◽  
Torque Development

Discriminatory Ability of Lower-Extremity Peak Torque and Rate of Torque Development in the Identification of Older Women With Slow Gait Speed

2018 ◽  
Vol 34 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Mary Hellen Morcelli ◽  
Dain Patrick LaRoche ◽  
Luciano Fernandes Crozara ◽  
Nise Ribeiro Marques ◽  
Camilla Zamfolini Hallal ◽  
...  
Keyword(s):  
Older Women ◽  
Gait Speed ◽  
Plantar Flexion ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscle Group ◽  
Rate Of Torque Development ◽  
Functional Gait ◽  
Hip Extension ◽  
Torque Development

The aim was to compare torque and rate of torque development of lower limb muscles between older women with functional and slow gait speeds to determine which muscle group is the best predictor of functional gait speed, and to establish strength thresholds needed for functional walking speed. Torque and rate of torque development of hip, knee, and ankle muscles were measured in older women who were divided in 2 groups according to gait speed: slow gait speed (<1.22 m·s−1) and functional gait speed (≥1.22 m·s−1). For each muscle group, 3 maximal isometric contractions were performed, and peak torque and rate of torque development were recorded. Older women with slow gait speed had lower peak torque than older women with functional gait speed for hip extension (28%), knee flexion (15%), knee extension (14%), and plantar flexion (16%) (allPs < .05). Older women with slow gait speed had lower peak rate of torque development for hip flexion (29%), hip extension (37%), knee flexion (34%), knee extension (33%), and plantar flexion (19%) (allPs < .05). Knee extension peak rate of torque development and hip extension peak torque were the better predictors of functional gait speed with thresholds of 2.96 N·m·s−1·kg−1and 1.26 N·m·kg−1, respectively.

scholarly journals Explosive Strength of the Knee Extensors: The Influence of Criterion Trial Detection Methodology on Measurement Reproducibility

2016 ◽  
Vol 50 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Johannes Dirnberger ◽  
Hans-Peter Wiesinger ◽  
Nicolas Wiemer ◽  
Alexander Kösters ◽  
Erich Müller
Keyword(s):  
Average Rate ◽  
Intraclass Correlation ◽  
Knee Extension ◽  
Knee Extensors ◽  
Time Intervals ◽  
Physically Active ◽  
Explosive Strength ◽  
Rate Of Torque Development ◽  
The One ◽  
Torque Development

AbstractThe present study was conducted to assess test-retest reproducibility of explosive strength measurements during single-joint isometric knee extension using the IsoMed 2000 dynamometer. Thirty-one physically active male subjects (mean age: 23.7 years) were measured on two occasions separated by 48–72 h. The intraclass correlation coefficient (ICC 2,1) and the coefficient of variation (CV) were calculated for (i) maximum torque (MVC), (ii) the peak rate of torque development (RTDpeak) as well as for (iii) the average rate of torque development (RTD) and the impulse taken at several predefined time intervals (0–30 to 0–300 ms); thereby explosive strength variables were derived in two conceptually different versions: on the one hand from the MVC-trial (version I), on the other hand from the trial showing the RTDpeak (version II). High ICC-values (0.80–0.99) and acceptable CV-values (1.9–8.7%) could be found for MVC as well as for the RTD and the impulse taken at time intervals of ≥100 ms, regardless of whether version I or II was used. In contrast, measurements of the RTDpeak as well as the RTD and the impulse taken during the very early contraction phase (i.e. RTD/impulse0–30ms and RTD/impulse0–50ms) showed clearly weaker reproducibility results (ICC: 0.53–0.84; CV: 7.3–16.4%) and gave rise to considerable doubts as to clinical usefulness, especially when derived using version I. However, if there is a need to measure explosive strength for earlier time intervals in practice, it is, in view of stronger reproducibility results, recommended to concentrate on measures derived from version II, which is based on the RTDpeak-trial.

Effects of isometric training on the elasticity of human tendon structures in vivo

2001 ◽  
Vol 91 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Keitaro Kubo ◽  
Hiroaki Kanehisa ◽  
Masamitsu Ito ◽  
Tetsuo Fukunaga
Keyword(s):  
Vastus Lateralis ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Vastus Lateralis Muscle ◽  
Electromechanical Delay ◽  
Isometric Training ◽  
Rate Of Torque Development ◽  
Human Tendon ◽  
Torque Development

The present study aimed to investigate the effect of isometric training on the elasticity of human tendon structures. Eight subjects completed 12 wk (4 days/wk) of isometric training that consisted of unilateral knee extension at 70% of maximal voluntary contraction (MVC) for 20 s per set (4 sets/day). Before and after training, the elongation of the tendon structures in the vastus lateralis muscle was directly measured using ultrasonography while the subjects performed ramp isometric knee extension up to MVC. The relationship between the estimated muscle force and tendon elongation ( L) was fitted to a linear regression, the slope of which was defined as stiffness of the tendon structures. The training increased significantly the volume (7.6±4.3%) and MVC torque (33.9±14.4%) of quadriceps femoris muscle. The L values at force production levels beyond 550 N were significantly shorter after training. The stiffness increased significantly from 67.5±21.3 to 106.2±33.4 N/mm. Furthermore, the training significantly increased the rate of torque development (35.8 ± 20.4%) and decreased electromechanical delay (−18.4±3.8%). Thus the present results indicate that isometric training increases the stiffness and Young's modulus of human tendon structures as well as muscle strength and size. This change in the tendon structures would be assumed to be an advantage for increasing the rate of torque development and shortening the electromechanical delay.

scholarly journals Training-specific functional, neural, and hypertrophic adaptations to explosive- vs. sustained-contraction strength training

2016 ◽  
Vol 120 (11) ◽  
pp. 1364-1373 ◽  
Author(s):  
Thomas G. Balshaw ◽  
Garry J. Massey ◽  
Thomas M. Maden-Wilkinson ◽  
Neale A. Tillin ◽  
Jonathan P. Folland
Keyword(s):  
Strength Training ◽  
Late Phase ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Neural Drive ◽  
Functional Changes ◽  
Sustained Contraction ◽  
Training Interventions ◽  
Isometric Knee Extension ◽  
Training Specificity

Training specificity is considered important for strength training, although the functional and underpinning physiological adaptations to different types of training, including brief explosive contractions, are poorly understood. This study compared the effects of 12 wk of explosive-contraction (ECT, n = 13) vs. sustained-contraction (SCT, n = 16) strength training vs. control ( n = 14) on the functional, neural, hypertrophic, and intrinsic contractile characteristics of healthy young men. Training involved 40 isometric knee extension repetitions (3 times/wk): contracting as fast and hard as possible for ∼1 s (ECT) or gradually increasing to 75% of maximum voluntary torque (MVT) before holding for 3 s (SCT). Torque and electromyography during maximum and explosive contractions, torque during evoked octet contractions, and total quadriceps muscle volume (QUADSVOL) were quantified pre and post training. MVT increased more after SCT than ECT [23 vs. 17%; effect size (ES) = 0.69], with similar increases in neural drive, but greater QUADSVOL changes after SCT (8.1 vs. 2.6%; ES = 0.74). ECT improved explosive torque at all time points (17–34%; 0.54 ≤ ES ≤ 0.76) because of increased neural drive (17–28%), whereas only late-phase explosive torque (150 ms, 12%; ES = 1.48) and corresponding neural drive (18%) increased after SCT. Changes in evoked torque indicated slowing of the contractile properties of the muscle-tendon unit after both training interventions. These results showed training-specific functional changes that appeared to be due to distinct neural and hypertrophic adaptations. ECT produced a wider range of functional adaptations than SCT, and given the lesser demands of ECT, this type of training provides a highly efficient means of increasing function.

Suppression of endogenous testosterone production attenuates the response to strength training: a randomized, placebo-controlled, and blinded intervention study

2006 ◽  
Vol 291 (6) ◽  
pp. E1325-E1332 ◽  
Author(s):  
Thue Kvorning ◽  
Marianne Andersen ◽  
Kim Brixen ◽  
Klavs Madsen
Keyword(s):  
Placebo Group ◽  
Strength Training ◽  
Intervention Study ◽  
Knee Extension ◽  
Strength Test ◽  
Whole Body ◽  
Gnrh Analog ◽  
Repetition Maximum ◽  
Isometric Knee Extension ◽  
Double Blinded

We hypothesized that suppression of endogenous testosterone would inhibit the adaptations to strength training in otherwise healthy men. Twenty-two young men with minor experience with strength training participated in this randomized, placebo-controlled, double-blinded intervention study. The subjects were randomized to treatment with the GnRH analog goserelin (3.6 mg) or placebo (saline) subcutaneously every 4 wk for 12 wk. The strength training period of 8 wk, starting at week 4, included exercises for all major muscles [3–4 sets per exercise × 6–10 repetitions with corresponding 6- to 10-repetition maximum (RM) loads, 3/wk]. A strength test, blood sampling, and whole body DEXA scan were performed at weeks 4 and 12. Endogenous testosterone decreased significantly ( P < 0.01) in the goserelin group from 22.6 ± 5.5 (mean ± SD) nmol/l to 2.0 ± 0.5 ( week 4) and 1.1 ± 0.6 nmol/l ( week 12), whereas it remained constant in the placebo group. The goserelin group showed no changes in isometric knee extension strength after training, whereas the placebo group increased from 240.2 ± 41.3 to 264.1 ± 35.3 Nm ( P < 0.05 within and P = 0.05 between groups). Lean mass of the legs increased 0.37 ± 0.13 and 0.57 ± 0.30 kg in the goserelin and placebo groups, respectively ( P < 0.05 within and P = 0.05 between groups). Body fat mass increased 1.4 ± 1.0 kg and decreased 0.6 ± 1.2 kg in the goserelin and placebo groups, respectively ( P < 0.05 within and between groups). We conclude that endogenous testosterone is of paramount importance to the adaptation to strength training.

Ultrasound Imaging of the Vastus Intermedius and Vastus Medialis Oblique Thickness for Assessment of Early Torque Development During Knee Extension

2020 ◽  
Vol 10 (7) ◽  
pp. 1557-1561
Author(s):  
Jaeho Yang ◽  
Yong Woo An ◽  
Eunwook Chang
Keyword(s):  
Isometric Contraction ◽  
Muscle Thickness ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Vastus Medialis ◽  
Maximal Voluntary Isometric Contraction ◽  
Rate Of Torque Development ◽  
Vastus Intermedius ◽  
Torque Development

The purpose of this study was to investigate relationships between knee extension torque (rate of torque development and peak torque) and quadriceps muscle thickness in healthy males and females. Thirty-six recreationally active and healthy individuals participated in the study. Portable ultrasound was used to image the dominant side of each quadriceps muscle (rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, vastus medialis oblique). After muscle thickness measurement, participants performed knee extension maximal voluntary isometric contraction. Rate of torque development was calculated from 0 to 50 (RTD50) and 0 to 200 (RTD200) milliseconds after onset of torque generation and peak torque was defined as maximum torque during maximal voluntary isometric contraction trials. A higher RTD50 value was found to be associated with greater vastus intermedius and vastus medialis oblique thicknesses, and a higher RTD200 with the thickness of all quadriceps muscles (p < 0.05). Finally, vastus medialis and vastus medialis oblique thicknesses were associated with a higher peak torque (p < 0.05). According to these results, the findings suggest to coaches that vastus intermedius and vastus medialis oblique thicknesses are critical to torque development during the early phase of knee extension contraction (RTD50), which is essential for executing athletic tasks and preventing injuries.

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